Forgejo keeps login sources in its database and exposes no REST endpoint for
them, so neither GitOps nor `tea` (whose admin command only manages users) can
set them. The in-pod CLI is the only supported writer.
This script wraps `gitea admin auth update-oauth` so the rename from the
Authentik-era label to `zitadel` is repeatable instead of a one-off command in
a shell history. Note in the header: the source name is both the button label
and the callback path, so ZITADEL must have both redirect URIs registered
before a rename.